var map = L.map(mapDiv, mapOptions);
var wmsLayer = L.tileLayer.wms('https://demo.boundlessgeo.com/geoserver/ows?', wmsOptions).addTo(map);

var wmsLayer = L.tileLayer.wms('https://demo.boundlessgeo.com/geoserver/ows?', {
    layers: "china_mercator_vec"
}).addTo(map);

